New science is breathing fresh life into the idea of a vaccine that works against all coronaviruses, including ones that could cause future pandemics.

Why it matters: No one wants to do the last year over again. But the road to a universal coronavirus vaccine is filled with hurdles, and there's no guarantee that coronaviruses would cause the next global pandemic.

• “I’d hate to have us get all dressed up for the wrong party,” said Jim Mayne, vice president of Science & Regulatory Advocacy at PhRMA.

State of play: Scientists have been attempting for years to make a universal flu vaccine, and have yet to be successful. But some experts say making a universal — or a pan-coronavirus vaccine — may be easier, especially given all that's been learned over the last year, and it's gaining attention from researchers.

• The NIH announced funding for projects related to pan-coronavirus vaccines in November, and two papers recently published —  one in Nature and one as a preprint — have been sources of optimism for the idea.
• Not only have we've learned more about coronaviruses in the last year, "we have technologies that make vaccine development much easier now than in the past," said Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security.
• If we do find a universal coronavirus or influenza vaccine, “it'd be something you had on the shelf...so as soon as you see the first inkling of an outbreak, you can be months and months ahead of time," NIAID Director Anthony Fauci said.

However, there are still plenty of hurdles that lie ahead in the race to create vaccines to prevent the next global pandemic. Among them:

1. There is still a lot we don't know

In the truest sense of the term, a "pan-coronavirus" vaccine would be effective against all coronaviruses, whether they cause pandemics or the common cold.

• That’s on the most ambitious side of the scientific spectrum. A potentially more achievable goal is creating vaccines that protect against specific kinds of coronaviruses, but not all of them.
• "I think we [can] have one for each family and combine them all together into an RNA vaccine," said Drew Weissman, a professor at University of Pennsylvania School of Medicine whose research laid the groundwork for mRNA vaccines.

Another option would be a vaccine that responds to the current coronavirus — SARS-COV-2 — and future variants of that virus, but also is broad enough to protect against some others, too.

• There’s some evidence that the current COVID-19 vaccines may do this, and next-generation vaccines could offer even broader protection than the current ones.

Zoom in: Weissman and researchers from Duke University School of Medicine, 3M and the Infectious Disease Research Institute recently made one such finding, which was published in Nature.

• Their COVID-19 vaccine candidate created an immune response that may protect against multiple SARS-COV-2 variants as well as some other coronaviruses.
• In an ideal scenario, "people will use it now to protect against variants, and it’ll also protect against future beta coronavirus pandemics," Weissman said.

Yes, but: “These are still relatively early-stage projects," said Cornell virologist and professor John Moore.

• "They haven’t succeeded in making a pan-coronavirus vaccine. They have a design for one that they’re testing. Come back in a year,” he added.

2. Incentivizing pharma investment is tricky

The further into the development pipeline a coronavirus vaccine is, the more expensive it will become to continue through that process.

• “One of the big reasons that a lot of promising vaccines never make it past Phase 1 clinical trials, at best, is because there’s no incentive for pharmaceutical companies to sponsor a Phase 3 trial, much less go through all the effort to bring something to market," said Angela Rasmussen, a virologist at the Vaccine and Infectious Disease Organization.
• “This is going to need huge investments upfront to really overcome those barriers," she said.

But it's unclear who is best suited to invest. The U.S. government’s financial de-risking of the development made investing in COVID-19 vaccines attractive and feasible for manufacturers, both logistically and financially.

• “There is a perverse incentive or disincentive for pharma to come up with a pan-coronavirus vaccine," said Corey Casper, CEO of the Infectious Disease Research Institute, pointing out that drug companies make more money the more shots they sell.
• Manufacturing complex vaccines is hard and expensive. "The main market for vaccines is going to be governments,” said former FDA Commissioner Mark McClellan. “This is the kind of thing you’d want to subsidize industry into supporting.”

3. Distribution planning would be unwieldy

To work as a proactive pandemic prevention measure against future global threats, such a vaccine would have to be brought to market, manufactured at enormous quantities, and then administered to the world's 8 billion people.

On top of that, the protection would have to last until the next pandemic.

A simpler option would be to have a recipe ready to go if — or, more likely, when — the next coronavirus pandemic hits.

• It's unclear how much time could be shaved off the record-breaking COVID-19 vaccination process. “Does that give you an advantage? It might, and it might not, if you’re counting on it to work and it doesn’t,” Mayne said.

What we're watching: If next-generation COVID vaccines offer broad protection against multiple coronaviruses, and are administered globally, that could be a way of killing two birds with one stone.

Bottom line: “Nobody wants to be caught out again, and we have to be in the position to respond," Moore said. "This pandemic could have been a lot worse, and if SARS-COV-2 had the lethality of MERS, a lot of us wouldn’t be around.”